I agree that there are always cases where curve fitting simply doesn't work. But I have seen some large curvy lines in a single plane that could have been curve fitted, that spanned over several feet of distance that were described as G1 segments that were no more than .005 inches long. That is simply bad Gcode.
Dave On 4/19/2012 12:45 PM, Les Newell wrote: > The big problem is that very often the curves in the drawing are not > true arcs. This is especially common in artistic and sign work. The > quality of the CAM output is directly dependent on the quality of the > input drawing. Drawings that contains just arcs and lines will generate > nice clean code. Drawings with lots of splines and other curves will > always generate big code. Some CAM packages try to do arc fitting on > curves but technically this is just as bad as breaking them up into > lines. You are compromising the accuracy of the final code. > > When it comes to 3D work, all bets are off because very often the final > tool path will not follow true arcs. > > Les > > > On 19/04/2012 17:31, Dave wrote: > >> I think this is a fairly common problem. There are a number Gcode >> generators out there that take curvy cutting patterns and turn >> them into huge files full of short G1 moves. The Gcode generator people >> expect the machine controller to gobble up the crappy G code and create >> smooth motions at high speeds. >> >> The one commercial application I ran into was for a vinyl cutter for >> sign making applications. They wanted to run at 1000 ipm while >> processing Gcode with segment lengths of a couple of thousands of an inch. >> It was crazy. Needless to say, a solution was never found. And their >> machines are still running slowly (the last I heard) due to the poor >> quality Gcode. >> >> Dave >> >> > > ------------------------------------------------------------------------------ > For Developers, A Lot Can Happen In A Second. > Boundary is the first to Know...and Tell You. > Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! > http://p.sf.net/sfu/Boundary-d2dvs2 > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------------ For Developers, A Lot Can Happen In A Second. Boundary is the first to Know...and Tell You. Monitor Your Applications in Ultra-Fine Resolution. Try it FREE! http://p.sf.net/sfu/Boundary-d2dvs2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
